Abstract: A dual chamber pumping apparatus and method for infusing fluids to a patient includes a disk having a fluid inlet and a fluid outlet. Resilient membranes are attached to opposite sides of the disk to establish dual pumping chambers, and a network of one-way valves connects the fluid inlet in alternating fluid communidation with the pumping chambers. A one-way outlet valve connects the pumping chambers alternately in fluid communication with the fluid outlet. The one-way valves utilize a hollow, elastomeric tube fixedly disposed in passageways within the disk for covering and uncovering respective ports in response to fluid pressure differentials on the inner and outer surfaces of the walls of the hollow, elastomeric tube.

Abstract: A disposable IV infusion device for ambulatory patients comprises a disk-shaped cover plate and a disk-shaped impeller plate which are interconnected by a stretched membrane that joins the edge of the cover plate with the edge of the impeller plate. The effect of the membrane is to urge the plates into juxtaposition. A fluid port is formed on the cover plate for fluid communication through the port with a collapsible fluid chamber established between the plates. Fluid, when injected into the chamber between the plates, is subsequently expelled through the port for controlled infusion to a patient as the membrane pulls the plates toward each other to collapse the chamber.

Abstract: A linear peristaltic pump includes a mechanism for maintaining linear flow of fluid through an I.V. tube. The mechanism comprises a casing carrying a rotatable camshaft having a plurality of cams spaced therealong in helical arrangement and a plurality of fingers coupled to the camshaft. A housing for establishing linear reciprocal movement of the fingers in response to rotation of the shaft establishes a moving zone of occlusion along a tube held against the fingers. Aligning means are included for establishing an axis of rotation of the camshaft which is slightly tilted with respect to the tube. This is accomplished by raising or lowering the upstream or the downstream end of the camshaft to prevent unwanted pressure from building up in the tube to reduce pulsatile flow and maintain linear flow. The aligning mechanism comprises a generally cylindrical bushing having an eccentric hole therethrough for carrying the hinged connection between the casing and the housing.

Abstract: A system for withdrawing a predetermined volume of fluid from a patient comprises a filter assembly which is connected in line for fluid communication between an artery and a vein of the patient. A pump having a fluid chamber is connected in fluid communication with a filtrate port of the filter. Operation of the pump causes the withdrawal of fluid from the filter and into the pump chamber at a preselected volumetric rate. Periodically, the pump is cycled to expel the withdrawn fluid from the pump chamber. The system further comprises a fluid collection device for collecting the expelled fluids and may include means for replenishing fluids to the patient.

Abstract: An improved dual mode peristaltic device is provided for infusing I.V. solutions to a patient through an I.V. tube. In a first mode of operation, the device functions as a peristaltic pump and in the second mode of operation it functions like a controller. Included in the device and associated with the I.V. tube is a pressure sensing strain gauge assembly that monitors dimensional changes in the outer diameter of the I.V. tube as an indication of fluid pressure changes in the tube. The strain gauge assembly is positioned relative to the device's peristaltic means to alternately monitor fluid pressure in a patent I.V. tube upstream and downstream from the gauge assembly. A pair of stationary fingers surround the strain gauge assembly to isolate it from the pulsitile nature of the peristaltic action of the device. In the first mode (pump mode), the device is programmed to alarm and cease operation when fluid pressure downstream from the gauge assembly reaches a preselected value.

Abstract: An IV tube activator for use with a peristaltic IV infusion pump comprises means that require the closure of a tube associated clamp upon engagement of the IV tube with the pump and upon any subsequent disengagement of the IV tube from the pump. The activator further comprises means which simultaneously move the tube associated clamp to open the IV tube when the pump is being operated.

Abstract: A detector for automatically determining the presence of air in a fluid line comprises a plurality of ON-OFF optical sensors selectively disposed in series along the axis of a portion of an I.V. tube according to their relative light sensitivity and according to their dependence upon direct or refracted light for activation. An alarm condition indicates air-in-line when predetermined individual sensors change their ON or OFF condition in accordance with a microprocessor programmed logic sequence.

Abstract: Apparatus is provided for regulating the flow of drops of fluid through a conduit. The apparatus includes first means responsive to the flow of fluid through the conduit for producing a turbulence in such flow when the flow is in a steady stream. The first means may include a tube having an inner wall shaped to produce such turbulence in the steady stream or may include a tube and a member disposed in the tube and having an outer wall shaped to produce such turbulence in the steady stream. The first means may be provided with a helical discontinuity to produce a twisting flow of the fluid in the steady stream for creating the turbulence.Second means are responsive to the flow of fluid in drops for sensing the rate of the drops. The second means may include a light source for directing light to the fluid and a sensor for receiving light from the fluid. Third means adjustably control the rate at which the drops of fluid flow through the conduit.

Abstract: Apparatus controls the rate of passage of fluid drops through a drip controller in accordance with a preset rate. When the rate of passage of the fluid drops is less than the preset rate, a stepper motor is incrementally operated at progressive instants of time to open the drip chamber until the measured rate is equal to the preset rate. When the rate of passage of the fluid drops is greater than the preset rate, the stepper motor is operated instantaneously to close the passage through a number of increments corresponding to the difference in the measured and preset rates.An alarm is energized when the stepper motor is positioned to provide for a maximum flow of fluid and the rate is still below the preset rate. An alarm is also energized when the passage is closed and the preset rate indicates a desired flow of fluid.An emergency motor is also provided to control the opening in the passage. Before the operation of the apparatus is instituted, the stepper motor is operated to close the drip chamber.

Abstract: Apparatus is provided for obtaining a controlled flow of fluid from a source to a patient. The apparatus includes a plunger movable vertically in a chamber and made from resilient material and having a pair of vertically spaced lands. The chamber defines a recess with the lands and the plunger in the space between the lands. Lubricating fluid is disposed in the recess. Fluid such as intravenous fluid is introduced into the chamber in one reciprocal movement of the plunger and is withdrawn from the chamber in the other reciprocal movement of the plunger. A porous washer filled with lubricating fluid is disposed in contiguous relationship to a particular one of the lands for providing an auxiliary reservoir of the lubricating fluid. Such washer may be contiguous to the lower one of the two (2) lands.

Abstract: Apparatus provides a controlled flow of fluid at particular rates from a source to a patient at controlled pressures of low value. The apparatus includes an input line connected to the source. An output line extends to the patient and implementing means such as a pump implements the flow of fluid from the input line to the output line at a particular rate. The source is disposed a particular distance above the implementing means to produce a particular pressure of the fluid at the implementing means and to provide this particular pressure to the fluid flowing to the patient.A bypass line is connected across the implementing means. Means in the bypass line, such as a chamber and a flexible diaphragm in the chamber, isolate the input side of the bypass line against the flow of fluid to the output side of the bypass line.

Abstract: Apparatus controls the maximum pressure of the fluid which can flow through a pump. The apparatus includes a disposable unit with an inlet for receiving fluid from a source, an outlet for transferring the fluid to a patient and a chamber communicating between the inlet and the outlet. A diaphragm across the chamber is constrained in accordance with the pressure of the fluid in the chamber. The diaphragm transmits the constraint to a stiffener.The disposable unit is removably attached to the pump casing. A knob is externally disposed on the pump casing and is adjustable to control the maximum force of the fluid in the disposable unit. The knob controls the force exerted on biasing means in a first direction. A force is also exerted against the biasing means in a second direction opposite to the first direction. This force is dependent upon the force on the stiffener.The biasing means may include a spring.

Abstract: A rate meter senses successive drops of fluid flowing through a conduit and produces gating periods with time durations corresponding to the period of time between such successive drops. The rate meter then determines the number of incremental time periods in each gating period. The rate meter generates the reciprocal of this determination to obtain an indication of the rate of fluid flow. The rate meter may be self-contained. It includes a housing having a vertically disposed channel constructed to retain the conduit and a horizontally disposed channel communicating with the vertically disposed channel. The horizontally disposed channel is constructed to receive a cross bar made from a resilient material and fixedly disposed on the conduit. The cross bar supports the rate meter in a freestanding relationship. The cross bar may be provided with slots near its ends to enhance its resiliency.

Abstract: A drop controller is provided for controlling the rate at which drops of a fluid flow to a patient. The drop controller includes a socket for receiving a cassette having a constrainable member adjustable in position. This constrainable member controls the size of an adjustable passage through which the fluid flows to the patient. The socket is defined by a plurality of spring fingers for releasably holding the cassette. A lever is mounted on the housing for the drop controller and is pivotable to a cocked position by the cassette when the cassette is disposed in the socket. The lever can be pivoted to a second position to obtain a removal of the cassette from the socket.An arrangement is also included for releasably and adjustably positioning the controller relative to a support pole. The arrangement includes a shaft and an arm at the end of the shaft for providing an engagement of the support pole between the arm and the housing of the controller.

Abstract: Apparatus is included in a system for controlling the flow of intravenous fluid from a source to a patient. Such apparatus is manually adjustable to vary the rate of such fluid flow. Desired rates of fluid flow may also be set in such system when the apparatus is included in the system. The system then overrides any previous manual adjustment of such apparatus and adjusts the rate of fluid flow in accordance with any such setting. When a desired rate of fluid flow has been preset into the system, the system then operates to adjust the rate of fluid flow in an instantaneous basis so that the desired rate of fluid flow maintained.The apparatus is removably disposed in the system for controlling the flow of fluid to the patient. Even after the adjustment by the system of the rate of fluid flow in accordance with any setting, the apparatus may be removed from the system to provide a rate of fluid flow in accordance with the manual adjustment of the apparatus.

Abstract: Apparatus is provided for assuring that fluid is introduced from a pump to a receiver, such as a patient, at a controlled and safe pressure. This arrangement includes conduit means, such as inlet and outlet lines, which extend from the pump to the receiver and which are included in a disposable unit. The disposable unit includes detent means cooperative with detent means in the pump to hold the disposable unit in releasable relationship with the pump.Resilient means such as diaphragm are disposed in the conduit means in the disposable unit. The resilient means expand or contract in accordance with the pressure of the fluid in the outlet line. Actuatable means such as an actuatable arm is disposed in the disposable unit and is captured in the conduit means and is positioned in abutting relationship with the diaphragm for movement with the diaphragm.